Camera Traps Catch Animals In the Act

Camera traps hidden in the Alaskan Arctic have captured tell-tale images of predatory animals raiding the nests of birds that migrate by the millions to the region each year. The guilty finger, however, points to us. According to the Wildlife Conservation Society, energy development activity in the region may benefit certain animal hunters to the detriment of other vulnerable species.

The WCS suspected as much, which is why the covert photographs were collected during the summers of 2010 and 2011 as part of ongoing studies to investigate the ecological footprint of oil exploration and other energy development activities. Conservationists wondered if such activites were affecting breeding birds that migrate to the region each year to nest during the brief arctic summers.

"Pictures are worth a thousand words and these photos speak volumes regarding the changing conditions that threaten migratory birds coming to the Arctic to breed," WCS North America Program Director Jodi Hilty was quoted as saying in a press release. "The photos are also a reminder of the value of undeveloped areas in the Arctic to birds from all over the world."

Hilty and colleagues indicate that we are "subsidizing" predators by providing opportunities for them to nest and den in, on, or under human-made structures.

(A common raven in the Prudhoe bay oil field caught by the camera trap removing an egg from a Lapland longspur nest.)

Arctic foxes den in culverts and under buildings in the oil fields, taking advantage of new-found homes that provide protective shelter for themselves and their young. In the past, ravens rarely nested in the Arctic because of the scarcity of nesting sites on the treeless tundra, but they are now opportunistically nesting on towers, eaves of buildings, and other structures across the transformed landscape. These "generalist" species gain additional benefits by consuming the garbage, road kills, and other sources of food brought by human activity.

(Near the Ikpikpuk River, the most common nest predators are arctic ground squirrels like this one caught by the camera.)

The camera traps were set up near both the Prudhoe Bay oil field and at a remote undeveloped area near the Ikpikpuk River in the National Petroleum Reserve-Alaska. The researchers chose these locations to determine whether or not the ravens and other predators were more commonly raiding the nests of birds in the oilfields as compared to remote areas.

(Grizzly bear sniffing around close to camera.)

Results showed that, for some species, survivorship and overall nest densities were higher at the undeveloped Teshekpuk site.

"The presence of people and structures enable these animals to live in areas that otherwise would not be preferred or suitable habitat, or to do so in greater numbers than would normally be the case," said WCS Scientist Joe Liebezeit. "As a result, they have more access to the nests of migratory birds and can exploit a vulnerable food source."

(Sometimes, the camera inadvertently captures images of other wildlife in the area including this caribou mother and calf.)

The Bureau of Land Management is now evaluating how best to balance wildlife protection and future energy development in the National Petroleum Reserve – Alaska. It's hoped that the camera trap images, along with other study findings, can help to better inform BLM's decision-making process.